+ *
+ * Dependencies:
+ * functions/global.php
+ * functions/strings.php.
+ *
+ * @copyright © 1999-2007 The SquirrelMail Project Team
+ * @license http://opensource.org/licenses/gpl-license.php GNU Public License
+ * @version $Id$
+ * @package squirrelmail
+ */
+
+
+/**
+ * Detect whether user is logged in
+ *
+ * Function is similar to is_logged_in() function. If user is logged in, function
+ * returns true. If user is not logged in or session is expired, function saves $_POST
+ * and PAGE_NAME in session and returns false. POST information is saved in
+ * 'session_expired_post' variable, PAGE_NAME is saved in 'session_expired_location'.
+ *
+ * Script that uses this function instead of is_logged_in() function, must handle user
+ * level messages.
+ * @return boolean
+ * @since 1.5.1
+ */
+function sqauth_is_logged_in() {
+ if ( sqsession_is_registered('user_is_logged_in') ) {
+ return true;
+ }
+
+ // First we store some information in the new session to prevent
+ // information-loss.
+ $session_expired_post = $_POST;
+ if (defined('PAGE_NAME'))
+ $session_expired_location = PAGE_NAME;
+ else
+ $session_expired_location = '';
+
+ if (!sqsession_is_registered('session_expired_post')) {
+ sqsession_register($session_expired_post,'session_expired_post');
+ }
+ if (!sqsession_is_registered('session_expired_location')) {
+ sqsession_register($session_expired_location,'session_expired_location');
+ }
+
+ session_write_close();
+
+ return false;
+}
+
+/**
+ * Reads and decodes stored user password information
+ *
+ * Direct access to password information is deprecated.
+ * @return string password in plain text
+ * @since 1.5.1
+ */
+function sqauth_read_password() {
+ sqgetGlobalVar('key', $key, SQ_COOKIE);
+ sqgetGlobalVar('onetimepad', $onetimepad,SQ_SESSION);
+
+ return OneTimePadDecrypt($key, $onetimepad);
+}
+
+/**
+ * Saves or updates user password information
+ *
+ * This function is used to update password information that SquirrelMail
+ * stores during existing web session. It does not modify password stored
+ * in authentication system used by IMAP server.
+ *
+ * Function must be called before any html output started. Direct access
+ * to password information is deprecated. Saved password information is
+ * available only to next executed SquirrelMail script. If your script needs
+ * access to saved password after sqauth_save_password() call, use returned
+ * OTP encrypted key.
+ * @param string $pass password
+ * @return string password encrypted with OTP. In case script wants to access
+ * password information before reloading page.
+ * @since 1.5.1
+ */
+function sqauth_save_password($pass) {
+ sqgetGlobalVar('base_uri', $base_uri, SQ_SESSION);
+
+ $onetimepad = OneTimePadCreate(strlen($pass));
+ sqsession_register($onetimepad,'onetimepad');
+ $key = OneTimePadEncrypt($pass, $onetimepad);
+ sqsetcookie('key', $key, false, $base_uri);
+ return $key;
+}
+
+/**
+ * Given the challenge from the server, supply the response using cram-md5 (See
+ * RFC 2195 for details)
+ *
+ * @param string $username User ID
+ * @param string $password User password supplied by User
+ * @param string $challenge The challenge supplied by the server
+ * @return string The response to be sent to the IMAP server
+ * @since 1.4.0
+ */
+function cram_md5_response ($username,$password,$challenge) {
+ $challenge=base64_decode($challenge);
+ $hash=bin2hex(hmac_md5($challenge,$password));
+ $response=base64_encode($username . " " . $hash) . "\r\n";
+ return $response;
+}
+
+/**
+ * Return Digest-MD5 response.
+ * Given the challenge from the server, calculate and return the
+ * response-string for digest-md5 authentication. (See RFC 2831 for more
+ * details)